An Empirical Study of the Traditional Mach Card Effect

Abstract
The traditional achromatic Mach card effect is an example of lightness inconstancy and a demonstration of how shape and lightness perception interact. We present a quantitative study of this phenomenon and explore the conditions under which it occurs. The results demonstrate that observers show lightness constancy only when sufficient information is available about the light-source position, and the perceptual task required of them is surface identification rather than direct colour-appearance matching. An analysis and comparison of these results with the chromatic Mach card effect (Bloj et al 1999 Nature402 877–879) demonstrate that the luminance effects of mutual illumination do not account for the change in lightness perception in the traditional Mach card.

This publication has 29 references indexed in Scilit: